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Environmental monitoring

A comprehensive program

An extensive environmental monitoring program was conducted during and after the REP to minimise impacts of the program, including:

  • Soil monitoring after bait distribution: 
    • Post-operational soil samples were collected to monitor residues of brodifacoum in the soil.
    • Results from soil testing showed no brodifacoum residue in any soil samples. All tests were conducted at a NATA accredited analytical laboratory.
  • Water monitoring after bait distribution:
    • To monitor brodifacoum levels in water, water samples were collected from streams, ocean water, groundwater and water tanks.
    • Results from all water testing showed no detectable brodifacoum residues. All tests were conducted at a NATA accredited analytical laboratory.
  • Additional samples of milk, eggs and fish were taken as a standard precaution prior to and after baiting.
    • Results showed no detectable brodifacoum residues in any egg or milk samples at any time. 
    • A small number of fish flesh samples returned very low levels of brodifacoum residue post-baiting (2019). These levels were well below the human health threshold of 450ug/kg. Routine post-REP fish sampling currently indicates no detectable brodifacoum residue in fish flesh.
    • Small numbers of fish liver samples continue to return brodifacoum residue on the lowest end of detectability. This is within the acceptable level for brodifacoum for seafood, as described in the LHI Human Health Risk Assessment Report developed by the NSW Chief Scientist. Fish testing will continue annually until no detectable residues remain.
  • Monitoring of weather in the lead up to and during the REP. This ensured bait was distributed safely and effectively and not during adverse weather conditions.
  • Monitoring non-target species deaths after bait distribution to ensure there were no unexpected impacts to endemic species.
  • Monitoring breakdown of baits after distribution. This provided confidence in bait breakdown prior to release of captive managed species (woodhens and currawongs).
  • Environmental surveys to provide evidence of species impacts and recovery.